Uranium glasses: I. Fundamental considerations

The principles involved in forming glasses containing uranium are discussed. Materials having low thermal neutron cross sections that could be useful components in a uranium glass are listed and their properties are discussed

Uranium glasses: II. Uranium silicate glasses

The maximum concentration of uranium dioxide (45 w/o) was determined for silicate glasses. A number of stable glasses were developed. The properties of a typical high-urania-content silicate glass are discussed

Uranium glasses III. uranium phosphate glasses

Abstract--The maximum concentration of uranium dioxide (40 w/o) was determined for stable, usable phosphate glasses. A number of such glasses were developed and probable structures are suggested. The properties of a typical high-urania-content phosphate glass are discussed and the effects of various intermediates and modifiers are considered

Elasticity and internal friction through the kilocycle range: reviwe and annotated bibliography

A review of techniques and fundamentals of Young\u27s modulus and internal friction measurements is presented. The effect of porosity on elasticity is extensively reviewed as are factors contributing to internal friction. An annotated bibliography of 377 entries covering elasticity and internal friction measurements through the kilocycle frequency range is included and accompanied by a keyword index

The Jolt-Pack Fabrication of Special Ceramic Ware

The jolt-pack method for fabrication of refractory crucibles and other shapes is described. The particle size distribution of the material to be packed has been found to be an important consideration in this method. Data are presented on packing densities of various graded fractions of beryllia and the development of a dense-packing mixture is described

Convective Fingering of an Autocatalytic Reaction Front

We report experimental observations of the convection-driven fingering instability of an iodate-arsenous acid chemical reaction front. The front propagated upward in a vertical slab; the thickness of the slab was varied to control the degree of instability. We observed the onset and subsequent nonlinear evolution of the fingers, which were made visible by a {\it p}H indicator. We measured the spacing of the fingers during their initial stages and compared this to the wavelength of the fastest growing linear mode predicted by the stability analysis of Huang {\it et. al.} [{\it Phys. Rev. E}, {\bf 48}, 4378 (1993), and unpublished]. We find agreement with the thickness dependence predicted by the theory.Comment: 11 pages, RevTex with 3 eps figures. To be published in Phys Rev E, [email protected], [email protected], [email protected]

Magnetospheric Multiscale Observations Of The Electron Diffusion Region Of Large Guide Field Magnetic Reconnection

We report observations from the Magnetospheric Multiscale (MMS) satellites of a large guide field magnetic reconnection event. The observations suggest that two of the four MMS spacecraft sampled t ..

Measurement of Thermal Properties by the Arc Image Furnace

A number of imaging furnace systems and sources are discussed with emphasis on the carbon arc image furnace. Several potential applications of the carbon arc image furnace in high temperature research are described and a new method of heat capacity determination is discussed

Magnetospheric Multiscale Satellites Observations Of Parallel Electric Fields Associated With Magnetic Reconnection

We report observations from the Magnetospheric Multiscale satellites of parallel electric fields (E (sub parallel)) associated with magnetic reconnection in the subsolar region of the Earth\u27s magnetopause. E (sub parallel) events near the electron diffusion region have amplitudes on the order of 100 millivolts per meter, which are significantly larger than those predicted for an antiparallel reconnection electric field. This Letter addresses specific types of E (sub parallel) events, which appear as large-amplitude, near unipolar spikes that are associated with tangled, reconnected magnetic fields. These E (sub parallel) events are primarily in or near a current layer near the separatrix and are interpreted to be double layers that may be responsible for secondary reconnection in tangled magnetic fields or flux ropes. These results are telling of the three-dimensional nature of magnetopause reconnection and indicate that magnetopause reconnection may be often patchy and/or drive turbulence along the separatrix that results in flux ropes and/or tangled magnetic fields